ipmi: don't grab locks in run-to-completion mode

This patch prevents deadlocks in IPMI panic handler caused by msg_lock
in smi_info structure and waiting_msgs_lock in ipmi_smi structure.

[cminyard@mvista.com: remove unnecessary memory barriers]
Signed-off-by: Konstantin Baydarov <kbaidarov@ru.mvista.com>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 4 insertions, 2 deletions

diff --git a/drivers/char/ipmi/ipmi_si_intf.c b/drivers/char/ipmi/ipmi_si_intf.c
index 30f535657342..657034febdaf 100644
--- a/drivers/char/ipmi/ipmi_si_intf.c
+++ b/drivers/char/ipmi/ipmi_si_intf.c
@@ -289,7 +289,8 @@ static enum si_sm_result start_next_msg(struct smi_info *smi_info)
 
         /* No need to save flags, we aleady have interrupts off and we
            already hold the SMI lock. */
-        spin_lock(&(smi_info->msg_lock));
+        if (!smi_info->run_to_completion)
+                spin_lock(&(smi_info->msg_lock));
 
         /* Pick the high priority queue first. */
         if (!list_empty(&(smi_info->hp_xmit_msgs))) {
@@ -329,7 +330,8 @@ static enum si_sm_result start_next_msg(struct smi_info *smi_info)
                 rv = SI_SM_CALL_WITHOUT_DELAY;
         }
         out:
-        spin_unlock(&(smi_info->msg_lock));
+        if (!smi_info->run_to_completion)
+                spin_unlock(&(smi_info->msg_lock));
 
         return rv;
 }